The best model I have seen for integrating DevOps in a company is where teams are created that span multiple groups. Instead of having a top-down approach to the deployment of operations, where you create the central teams, the standards, the bills, etc., and then push it down, the central DevOps team hires or trains DevOps engineers and then allocates them to each team.
The logic is that each team spends a certain amount of time with a DevOp engineer, who trains the teams in DevOp activities and best practices, and thereby embeds the best practices in the development life cycle.
The result is horizontal teams, which have several advantages. They have two masters: they answer to DevOps but they also answer to the team lead, and they share best practice. The creation of horizontal teams is a much better way to scale, and it encourages teams to collaborate. The teams know they aren't required to spend all their time working in DevOps, and they know there is someone who can help them.